Nowadays, mobile terminals are widely used, largely due to their mobility. For example, mobile communication terminals that can perform voice communication while moving are used by more than 85% of the Korean population.
The mobile communication terminal includes an input device for receiving user input, such as a keypad, touch pad, and wheel, and a display unit for displaying user input and other data. The display unit displays activation of a specific application and screen conversion corresponding to a key event or a touch event occurring in the input device. Further, the mobile communication terminal includes a radio frequency (RF) unit for transmitting a voice signal input by a user to another mobile communication terminal and for receiving a voice signal from another mobile communication terminal.
The mobile communication terminal has been developed to perform various mechanical operations according to a user's preference. For example, various types of mobile communication terminals are available, such as a folder type in which a first body and a second body are connected by a hinge and the second body performs a rotation operation by a predetermined angle about the hinge, and a slide type in which a first body and a second body are disposed to face each other and the second body performs a sliding operation or a rotation operation relative to an upper part and a lower part of the first body.
However, due to a trend of slimming the terminal, it is difficult to appropriately dispose an antenna in a sliding up and down structure of a conventional slide type mobile communication terminal and in a folding open and closed structure of a conventional folder type mobile communication terminal. Further, in order to reinforce strength in a slim structure of the sliding up and down structure of the conventional slide type mobile communication terminal and of the folding open and closed structure of the conventional folder type mobile communication terminal, a case of a metal material, such as magnesium and aluminum, is generally used. Accordingly, when a conventional mobile terminal uses one antenna at a mechanical operation, i.e., at a sliding up and down operation or a folding open and closed operation of the mobile terminal, a radiation pattern changes according to a disposition environment of the case of a metal material. In the slide type mobile terminal, according to a disposition of a speaker, keypad, and display unit mounted in the mobile terminal, at sliding up and down, radiation efficiency of an antenna is reduced. Further, in a mobile music phone, in addition to a receiver, a speaker having a large resonance space is disposed, and in a mobile message phone, because a large keypad and a structure for firmly supporting the large keypad are formed, the mobile message phone has an external form that is detrimental to radiation efficiency of an antenna.
FIG. 1A is a diagram illustrating a radiation pattern after a slide type mobile terminal performs a slide opening operation, and FIG. 1B is a diagram illustrating a radiation pattern before a slide type mobile terminal performs a slide opening operation.
As shown in FIGS. 1A and 1B, a conventional mobile terminal has an extremely distorted antenna radiation pattern in both the open and closed positions. In order to solve the problem, conventionally, a mobile terminal having two antennas, a switch for selecting each antenna, and signal lines for connecting each antenna, has been suggested. However, such a mobile terminal is not consistent with a demand for reducing a thickness and size of the mobile terminal, in which a separate space for forming an additional antenna and switch and signal lines for connecting each antenna cannot easily be secured.